A parallel group screening method for single cells

Abstract

The invention discloses a parallel group screening method of monomer batteries, which includes: determining the actual capacity and DC internal resistance of all monomer batteries in a normal temperature environment and a low temperature environment, and determining the battery capacity and DC internal resistance of all monomer batteries in a normal temperature environment and a low temperature environment. The capacity threshold range and internal resistance threshold range of the battery are used to filter the single batteries that meet the screening conditions into a group. Multiple single cells screened as a group can be connected in parallel to form a battery pack, which can make the consistency between the single cells in the battery pack higher and improve the performance of the battery pack.

Description

technical field

[0001] The invention belongs to the field of battery systems of new energy vehicles, and in particular relates to a parallel group screening method of single batteries. Background technique

[0002] With the characteristics of "electrification and zero emission", electric vehicles have become the main development direction of the new energy vehicle industry. In order to ensure the healthy development of the electric vehicle industry, the application of power batteries has attracted more and more attention. In order to meet the power and endurance requirements of automobiles, it is usually necessary to connect multiple single batteries in series or in parallel to form a battery pack, and then connect multiple battery packs to form a power battery to increase the external voltage and capacity of the battery system. output capacity. In the mass production process of single cells, due to problems such as production materials and processes, it is difficult to ens...

Examples

Embodiment Construction

[0019] Such as figure 1 The parallel group screening method of the single cells shown includes:

[0020] Step 1. Determine the actual capacity and DC internal resistance of all single batteries under normal temperature environment and low temperature environment

[0021] Under the environment of 25°C, conduct a constant current discharge test on all the single batteries in the first fully charged state with a current of 1 / 3C, and obtain the actual capacity Q of each single battery under the environment of 25°C; among them, the first fully charged state A single battery refers to a single battery that is fully charged with a constant current of 1 / 3C at 25°C and left to stand for 4 hours at 25°C.

[0022] Under the environment of 25°C, discharge all the single cells in the first fully charged state with a constant current of 1 / 3C. During the constant current discharge process, when the SOC of the single cells is 90%, 60%, and 10% Add 1C current to conduct 10-second pulse disch...

technical field

[0001] The invention belongs to the field of battery systems of new energy vehicles, and in particular relates to a parallel group screening method of single batteries. Background technique

[0002] With the characteristics of "electrification and zero emission", electric vehicles have become the main development direction of the new energy vehicle industry. In order to ensure the healthy development of the electric vehicle industry, the application of power batteries has attracted more and more attention. In order to meet the power and endurance requirements of automobiles, it is usually necessary to connect multiple single batteries in series or in parallel to form a battery pack, and then connect multiple battery packs to form a power battery to increase the external voltage and capacity of the battery system. output capacity. In the mass production process of single cells, due to problems such as production materials and processes, it is difficult to ens...

Examples

Embodiment Construction

[0019] Such as figure 1 The parallel group screening method of the single cells shown includes:

[0020] Step 1. Determine the actual capacity and DC internal resistance of all single batteries under normal temperature environment and low temperature environment

[0021] Under the environment of 25°C, conduct a constant current discharge test on all the single batteries in the first fully charged state with a current of 1 / 3C, and obtain the actual capacity Q of each single battery under the environment of 25°C; among them, the first fully charged state A single battery refers to a single battery that is fully charged with a constant current of 1 / 3C at 25°C and left to stand for 4 hours at 25°C.

[0022] Under the environment of 25°C, discharge all the single cells in the first fully charged state with a constant current of 1 / 3C. During the constant current discharge process, when the SOC of the single cells is 90%, 60%, and 10% Add 1C current to conduct 10-second pulse disch...

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